/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *
 *    https://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License.
 */
package org.grails.cli.compiler;

import java.net.MalformedURLException;
import java.net.URI;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import groovy.grape.Grape;
import org.codehaus.groovy.ast.ASTNode;
import org.codehaus.groovy.ast.AnnotationNode;
import org.codehaus.groovy.ast.expr.ConstantExpression;
import org.codehaus.groovy.ast.expr.Expression;
import org.codehaus.groovy.ast.expr.ListExpression;
import org.codehaus.groovy.control.messages.Message;
import org.codehaus.groovy.control.messages.SyntaxErrorMessage;
import org.codehaus.groovy.syntax.SyntaxException;

import org.apache.maven.model.Dependency;
import org.apache.maven.model.Model;
import org.apache.maven.model.Parent;
import org.apache.maven.model.Repository;
import org.apache.maven.model.building.DefaultModelBuilder;
import org.apache.maven.model.building.DefaultModelBuilderFactory;
import org.apache.maven.model.building.DefaultModelBuildingRequest;
import org.apache.maven.model.resolution.InvalidRepositoryException;
import org.apache.maven.model.resolution.ModelResolver;
import org.apache.maven.model.resolution.UnresolvableModelException;

import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;

import org.grails.cli.compiler.dependencies.MavenModelDependencyManagement;
import org.grails.cli.compiler.grape.DependencyResolutionContext;
import org.grails.cli.groovy.DependencyManagementBom;

/**
 * {@link org.codehaus.groovy.transform.ASTTransformation} for processing
 * {@link DependencyManagementBom @DependencyManagementBom} annotations.
 *
 * @author Andy Wilkinson
 * @since 1.3.0
 */
@Order(DependencyManagementBomTransformation.ORDER)
@SuppressWarnings("deprecation")
public class DependencyManagementBomTransformation extends AnnotatedNodeASTTransformation {

    /**
     * The order of the transformation.
     */
    public static final int ORDER = Ordered.HIGHEST_PRECEDENCE + 100;

    private static final Set<String> DEPENDENCY_MANAGEMENT_BOM_ANNOTATION_NAMES = Collections
        .unmodifiableSet(new HashSet<>(
                Arrays.asList(DependencyManagementBom.class.getName(), DependencyManagementBom.class.getSimpleName())));

    private final DependencyResolutionContext resolutionContext;

    public DependencyManagementBomTransformation(DependencyResolutionContext resolutionContext) {
        super(DEPENDENCY_MANAGEMENT_BOM_ANNOTATION_NAMES, true);
        this.resolutionContext = resolutionContext;
    }

    @Override
    protected void processAnnotationNodes(List<AnnotationNode> annotationNodes) {
        if (!annotationNodes.isEmpty()) {
            if (annotationNodes.size() > 1) {
                for (AnnotationNode annotationNode : annotationNodes) {
                    handleDuplicateDependencyManagementBomAnnotation(annotationNode);
                }
            }
            else {
                processDependencyManagementBomAnnotation(annotationNodes.get(0));
            }
        }
    }

    private void processDependencyManagementBomAnnotation(AnnotationNode annotationNode) {
        Expression valueExpression = annotationNode.getMember("value");
        List<Map<String, String>> bomDependencies = createDependencyMaps(valueExpression);
        updateDependencyResolutionContext(bomDependencies);
    }

    private List<Map<String, String>> createDependencyMaps(Expression valueExpression) {
        Map<String, String> dependency = null;
        List<ConstantExpression> constantExpressions = getConstantExpressions(valueExpression);
        List<Map<String, String>> dependencies = new ArrayList<>(constantExpressions.size());
        for (ConstantExpression expression : constantExpressions) {
            Object value = expression.getValue();
            if (value instanceof String) {
                String[] components = ((String) expression.getValue()).split(":");
                if (components.length == 3) {
                    dependency = new HashMap<>();
                    dependency.put("group", components[0]);
                    dependency.put("module", components[1]);
                    dependency.put("version", components[2]);
                    dependency.put("type", "pom");
                    dependencies.add(dependency);
                }
                else {
                    handleMalformedDependency(expression);
                }
            }
        }
        return dependencies;
    }

    private List<ConstantExpression> getConstantExpressions(Expression valueExpression) {
        if (valueExpression instanceof ListExpression) {
            return getConstantExpressions((ListExpression) valueExpression);
        }
        if (valueExpression instanceof ConstantExpression &&
                ((ConstantExpression) valueExpression).getValue() instanceof String) {
            return Arrays.asList((ConstantExpression) valueExpression);
        }
        reportError("@DependencyManagementBom requires an inline constant that is a string or a string array",
                valueExpression);
        return Collections.emptyList();
    }

    private List<ConstantExpression> getConstantExpressions(ListExpression valueExpression) {
        List<ConstantExpression> expressions = new ArrayList<>();
        for (Expression expression : valueExpression.getExpressions()) {
            if (expression instanceof ConstantExpression &&
                    ((ConstantExpression) expression).getValue() instanceof String) {
                expressions.add((ConstantExpression) expression);
            }
            else {
                reportError("Each entry in the array must be an inline string constant", expression);
            }
        }
        return expressions;
    }

    private void handleMalformedDependency(Expression expression) {
        Message message = createSyntaxErrorMessage(
                String.format("The string must be of the form \"group:module:version\"%n"), expression);
        getSourceUnit().getErrorCollector().addErrorAndContinue(message);
    }

    private void updateDependencyResolutionContext(List<Map<String, String>> bomDependencies) {
        URI[] uris = Grape.getInstance().resolve(null, bomDependencies.toArray(new Map<?, ?>[0]));
        DefaultModelBuilder modelBuilder = new DefaultModelBuilderFactory().newInstance();
        for (URI uri : uris) {
            try {
                DefaultModelBuildingRequest request = new DefaultModelBuildingRequest();
                request.setModelResolver(new GrapeModelResolver());
                request.setModelSource(new org.apache.maven.model.building.UrlModelSource(uri.toURL()));
                request.setSystemProperties(System.getProperties());
                Model model = modelBuilder.build(request).getEffectiveModel();
                this.resolutionContext.addDependencyManagement(new MavenModelDependencyManagement(model));
            }
            catch (Exception ex) {
                throw new IllegalStateException("Failed to build model for '" + uri + "'. Is it a valid Maven bom?",
                        ex);
            }
        }
    }

    private void handleDuplicateDependencyManagementBomAnnotation(AnnotationNode annotationNode) {
        Message message = createSyntaxErrorMessage(
                "Duplicate @DependencyManagementBom annotation. It must be declared at most once.", annotationNode);
        getSourceUnit().getErrorCollector().addErrorAndContinue(message);
    }

    private void reportError(String message, ASTNode node) {
        getSourceUnit().getErrorCollector().addErrorAndContinue(createSyntaxErrorMessage(message, node));
    }

    private Message createSyntaxErrorMessage(String message, ASTNode node) {
        return new SyntaxErrorMessage(new SyntaxException(message, node.getLineNumber(), node.getColumnNumber(),
                node.getLastLineNumber(), node.getLastColumnNumber()), getSourceUnit());
    }

    private static class GrapeModelResolver implements ModelResolver {

        @Override
        public org.apache.maven.model.building.ModelSource resolveModel(Parent parent)
                throws UnresolvableModelException {
            return resolveModel(parent.getGroupId(), parent.getArtifactId(), parent.getVersion());
        }

        @Override
        public org.apache.maven.model.building.ModelSource resolveModel(Dependency dependency)
                throws UnresolvableModelException {
            return resolveModel(dependency.getGroupId(), dependency.getArtifactId(), dependency.getVersion());
        }

        @Override
        public org.apache.maven.model.building.ModelSource resolveModel(String groupId, String artifactId,
                String version) throws UnresolvableModelException {
            Map<String, String> dependency = new HashMap<>();
            dependency.put("group", groupId);
            dependency.put("module", artifactId);
            dependency.put("version", version);
            dependency.put("type", "pom");
            try {
                return new org.apache.maven.model.building.UrlModelSource(
                        Grape.getInstance().resolve(null, dependency)[0].toURL());
            }
            catch (MalformedURLException ex) {
                throw new UnresolvableModelException(ex.getMessage(), groupId, artifactId, version);
            }
        }

        @Override
        public void addRepository(Repository repository) throws InvalidRepositoryException {
        }

        @Override
        public void addRepository(Repository repository, boolean replace) throws InvalidRepositoryException {
        }

        @Override
        public ModelResolver newCopy() {
            return this;
        }

    }

}
